Sections of a Differential Spectrum

Global sections of structure sheafs of Keigher rings

In answer to a question of J. Kovacic, we show that for any Keigher ring its differential spectrum coincides with differential spectrum of global sections of structure sheaf.

Derivations of the Algebra of Sections of Superalgebra Bundles

In this paper we review the concepts of the superalgebra, superderivation and some properties of them. We will define algebraic and differential superderivations on a superalgebra and will prove some theorems about them, Then we consider a superalgebra bundle, that is an algebra bundle which its fibers are superalgebras and then characterize the superderivations of the algebra of sections of th...

On the Spectral Properties of Degenerate Non-selfadjoint Elliptic systems of Differential Operators

به کاربردن تقریب دو حالته در تولید هیدروژن با فرود آمدن پروتون بر روی پوزیترونیوم

Although there is no experimental data available for antihydrogen formation following antiprotons impact on positroium atoms, as a charge transfer reaction, at incident energies which are suitable for antimatter high-precision spectroscopic studies, measurements were carried out for its charge-conjugate reaction i. e. hydrogen formation, by protons impact on positronium. In this study, a two-st...

Pilomatricoma: A clinicopathological review of 22 cases diagnosed in Hamadan Sina Hospital between 1992 and 1999

Background: Pilomatricoma, the most common hair follicle tumor, has a wide variety of clinicopathological characteristics and is often misdiagnosed. Objective: The aim of this study was to explain the clinical and histological spectrum of tumor in order to help for its better diagnosis. Patients and Methods: In a retrospective descriptive study, the clinical and histological features of pilomat...